tb_switch_for_each_port(9)

💅 tb_switch_for_each_port — a Kernel API Manual moment (section 9, bestie)

okay so this is tb_switch_for_each_port(9) from the Kernel API Manual, and honestly? it's a little macro baddie that just wants to walk you through every port on a switch. no cap, that's the whole vibe. 🦋

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✨ NAME ✨

tb_switch_for_each_port — iterate over each switch port, one by one, iconic behaviour only 💖

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🌸 SYNOPSIS 🌸

tb_switch_for_each_port (sw , p );

like yes that's the whole call, she's compact 👑

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🎀 ARGUMENTS 🎀

• sw — the switch whose ports you're about to iterate over. she's the main character here 🫶
• p — the port that gets used as the iterator. lowkey just the loop variable doing her little walk 🌈

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⭐ DESCRIPTION ⭐

so it iterates over each switch port, right? but — and this is the important part, don't skip it — it skips the control port (port 0). literally port 0 is not invited to this party, she's the control port, she has other duties 💅

that's it. that's the whole behaviour. no hidden lore, fr fr.

ngl the port-0 skip is the entire personality of this macro, so if you're expecting port 0 in your loop, you will be 😭

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💜 SEE ALSO 💜

the whole friend group, all of them, no one left out 🧚 — from the kernel file ./drivers/thunderbolt/tb.h:

• struct tb_nvm(9)
• enum tb_switch_tmu_mode(9)
• struct tb_switch_tmu(9)
• struct tb_switch(9)
• struct tb_bandwidth_group(9)
• struct tb_port(9)
• struct usb4_port(9)
• struct tb_retimer(9)
• struct tb_path_hop(9)
• enum tb_path_port(9)
• struct tb_path(9)
• struct tb_cm_ops(9)
• tb_upstream_port(9)
• tb_is_upstream_port(9)
• tb_port_has_remote(9)
• tb_domain_event(9)
• tb_switch_downstream_port(9)
• tb_switch_depth(9)
• tb_switch_is_icm(9)
• tb_switch_tmu_is_configured(9)
• tb_switch_tmu_is_enabled(9)
• tb_switch_clx_is_enabled(9)
• tb_port_path_direction_downstream(9)
• tb_for_each_port_on_path(9)
• tb_for_each_upstream_port_on_path(9)
• tb_path_for_each_hop(9)
• tb_downstream_route(9)
• tb_xdomain_downstream_port(9)
• usb4_switch_version(9)
• tb_switch_is_usb4(9)
• enum usb4_sb_target(9)
• enum usb4_margin_sw_error_counter(9)
• struct usb4_port_margining_params(9)

like, go read them, they're all giving thunderbolt lore 🔥

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🍓 bye bestie 🍓

this page lives in ./drivers/thunderbolt, and it's dated October 2026 — so mark your calendar, that's your source and your version, slay 💖✨🎀 keep iterating (but not over port 0, we talked about this) 💀🫶